Leaf through the premier custom software development companies in London that customize, maintain and/or build high-quality solutions, mobile applications and more. Filter listings by reviews, pricing, team size to find the ideal team for your project requirements and budget.
Best London Software Development Firm Rankings
6 Companies-Rankings updated: September 12, 2026
DesignRush vets all agencies based on professional qualifications and verified customer feedback to help you choose confidently. Some featured agencies maintain paid sponsorships.
We build mobile apps, web platforms & AI workflows for organisations doing good in the world.
3 Sided Cube is a global mobile app and digital development company with a passion for Tech For Good, championing the genius over the generic to build life-saving, life-changing digital solutions...
Top Services:
Mobile App Development
Software Development
Web Development
AI Development
Digital Services
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Location
London, United Kingdom
Number of Employees
50 - 99
Average Hourly Rate
$150/hr
Minimal Budget
$50,000 & Up
Portfolios Count
5 Projects Listed
3 Sided Cube Services
Mobile App Development
Software Development
Web Development
AI Development
Digital Services
UI/UX Design
Digital Strategy
Data sourced from the agency's DesignRush profile, its website, and other relevant accounts
American Red Cross
Surfers Against Sewage
Omaze
Vodafone | Glastonbury Festival
LUSH
Global Forest Watch
The World Resources Institute
University Of Bristol
GDPC
Wonderbly
Data sourced from the agency's DesignRush profile
3 Sided Cube Reviews & Testimonials
Si Muddell Review from Google
4.0★
Si Muddell's Review Sourced from Google
Fantastically positive and driven team who on every interaction you just know care deeply about a) what they do b) what they deliver and c) ultimately the experience the end user will have.Hugely impressed with their personal, creative and energy driven approach at the pitch stage, I commissioned 3SC to help us better scope an app. Their task was to take an in-house developed app prototype, and turn it into a fully fledged technical specification with user stories, MoSCoW prioritisation, costs, and an updated look and feel; all done with audience need at the heart.Myself and the wider team have nothing but very good things to say about 3SC. When reflecting on an agency to work with, loads say they can do it, some can actually do what they say they can do, even less do it in the spirit of real partnership and mutually respect/drive. 3SC do all of these excellently. I highly recommend them.
Oliver Morrison Review from Google
5.0★
Oliver Morrison's Review Sourced from Google
A passionate team of insanely talented experts, producing industry leading technology for good causes. Highly recommend.
Kev Borrill Review from Google
5.0★
Kev Borrill's Review Sourced from Google
Great Digital agency with a passion for making great mobile apps in the Tech for good industry
Reviews verified by DesignRush and sourced from the agency's profile View All Reviews
Kellton is a publicly listed, CMMI Level 5, and ISO 9001:2015 certified global company, providing cutting-edge AI and digital transformation solutions and services in strategy, consulting, digital, and technology...
Top Services:
Big Data Analytics
Software Development
AI Development
Mobile App Development
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Location
London, United Kingdom
Number of Employees
1000 & Up
Average Hourly Rate
$50/hr
Minimal Budget
$50,000 & Up
Portfolios Count
8 Projects Listed
Kellton Services
Big Data Analytics
Software Development
AI Development
Mobile App Development
Data sourced from the agency's DesignRush profile, its website, and other relevant accounts
Max Life
Real Estate - Foxtons
Non Profits - Unicef
Govt. of Mauritius
Walmart
Data sourced from the agency's DesignRush profile
Kellton Reviews & Testimonials
Priyanshi Verma Review from Google
1.0★
Priyanshi Verma's Review Sourced from Google
Unprofessional, Mentally Draining, and Disrespectful Work CultureMy overall experience with this company was extremely toxic. During my short tenure, I observed several deeply unprofessional practices that left a lasting negative impact on me:•Salaries were often delayed, without prior communication or explanation.•There were unexplained deductions in monthly salary, and any attempts to raise concerns were either ignored or dismissed by HR.•The HR department was shockingly rude. I personally witnessed employees being humiliated or emotionally broken when they decided to resign — some even left in tears.•No proper Full and Final Settlement (FNF) or professional offboarding process was followed. It’s like once you resign, you’re treated as if you never existed.•Even after resignation, the company continued to send intimidating and threatening emails and begging for small amount of money like 20k, showing a complete lack of empathy — especially towards people who were already in a tough personal or financial situation.If you’re considering joining, please rethink carefully. Make sure everything is documented in writing — verbal promises mean nothing here. A company’s real face shows not when you join, but when you try to leave. And unfortunately, this one shows zero professionalism, zero compassion, and zero respect for employees.
Nani Sweety Review from Google
1.0★
Nani Sweety's Review Sourced from Google
I took 4 rounds of Interview for US IT Recruiter position..1st is virtual, 2nd round is In-person, 3rd and 4th are telephonic...They did not give any feedback.Worst experience, please don't attend interviews.waste of time
varsha kaushal Review from Google
1.0★
varsha kaushal's Review Sourced from Google
One of the worst organisation I have ever experienced . Exit process is worst moreover company doesn’t respond on your final f&f queries and literally one has to chase to get their full n final payment. Depending upon clients requirement organisation and their leaders push their employees and even salary is deducted if it is not billed as per clients need. Pathetic to be honest. Lala companies are doing better than this in country.
Reviews verified by DesignRush and sourced from the agency's profile View All Reviews
Creating Mobile Apps That Digitally Transform Business
Sugar Rush is a Mobile App Agency that provides mobile app development services to clients in the UK, Ireland, Europe, and the US. They have received recognition as the "UK App Agency of the Year" and have won 'App of The Year' awards for three consecutive years in Northern Ireland...
Top Services:
Mobile App Development
Web Design
Software Development
VR/AR
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Location
London, United Kingdom
Number of Employees
Under 49
Minimal Budget
$50,000 & Up
Portfolios Count
1 Project Listed
Sugar Rush Services
Mobile App Development
Web Design
Software Development
VR/AR
Data sourced from the agency's DesignRush profile, its website, and other relevant accounts
BUNZL
BBC
Radio Times
TopGear
Game of Thrones
Stryker
Olympus
Angling Direct
Data sourced from the agency's DesignRush profile
Sugar Rush Reviews & Testimonials
Dean Lyttle Review from Google
5.0★
Dean Lyttle's Review Sourced from Google
On behalf of AES Global Ltd -Moving our app development locally was a key focus for us in 2020. After extensive research into local companies and speaking to them all Ali, Danielle and the whole team at Sugar Rush most definitely came out on top.Their company culture and attention to detail was what caught our eye first which was followed closely on their project management skills.We are currently working on our 4th project together and i am still amazed with their dedication to learn our product inside out so they truly understand how it should function with the app and provide new ideas and better flows than what we had before.We have dealt with a large number of different colleagues within Sugar Rush and every single one of them are a credit to the company and provide a brilliant customer experience.Here is to the last 2 year partnership with many more years to follow. Thank you Sugar Rush for your partnership and helping to modernise and optimise our app platform.
Reviews verified by DesignRush and sourced from the agency's profile View All Reviews
NJI Media is a reputable interactive agency that specializes in creating stunning designs, web development, multimedia production and effective online communications strategies. We offer these services to various high-profile corporate, political, and non-profit organizations across the United States...
Top Services:
Branding
Web Design
UI/UX Design
Web Development
Digital Services
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Location
London, United Kingdom
Number of Employees
Under 49
Average Hourly Rate
$199/hr
Minimal Budget
$50,000 & Up
NJI Media Services
Branding
Web Design
UI/UX Design
Web Development
Digital Services
Software Development
Digital Strategy
Data sourced from the agency's DesignRush profile, its website, and other relevant accounts
Were a digital creative agency, built to amplify the purpose of charities
Were a digital creative agency, built to amplify the purpose of charities...
Top Services:
Web Design
UI/UX Design
Branding
Web Development
WordPress Website Design
Show more
Location
London, United Kingdom
Number of Employees
Under 49
Average Hourly Rate
$140/hr
Minimal Budget
$50,000 & Up
Studio Republic Services
Web Design
UI/UX Design
Branding
Web Development
WordPress Website Design
Mobile App Development
Digital Strategy
Design Services
Digital Services
Software Development
Data sourced from the agency's DesignRush profile, its website, and other relevant accounts
ALCOHOL CHANGE UK
BLISS
CHILDREN WITH CANCER UK
DUCHENNE UK
LONDON CYCLING CAMPAIGN
THE WI
TRANSPORT FOR ALL
Data sourced from the agency's DesignRush profile
Studio Republic Reviews & Testimonials
Gemma Jones Review from Google
5.0★
Gemma Jones's Review Sourced from Google
The team at Studio Republic are absolutely fantastic, always quick to respond, explore new ways to achieve results, plus creative and forward-thinking. The Account Management from Laura is exceptional... I thought I was organised, but she takes it to the next level!
Clive Lustor Review from Google
1.0★
Clive Lustor's Review Sourced from Google
This is not a trustworthy, ethical or stable business.Studio republic abused the furlough scheme, amongst other things they hired a new account manager while still using furlough for the current account manager.Avoid at all costs!
Paul Coulson Review from Google
5.0★
Paul Coulson's Review Sourced from Google
We chose Studio Republic to build our new website as they had a great track record of working with similar non-profit environmental organisations like ourselves. They provided an excellent service from start to finish and were a pleasure to work with.Our finished website not only looks great but it has also streamlined our processes which gives our members and staff a much better user experience.
Reviews verified by DesignRush and sourced from the agency's profile View All Reviews