Brantum | Software & Marketing Agency

Mobile App

Growth Hacking

React Native app with viral PLG loops built in from sprint one — performance UA campaigns achieved 50,000 users in 90 days at £0.32 CPI.

Project Details

This consumer tech client had a strong product concept — a utility app for a well-defined audience — and a £150,000 UA budget to acquire their first 50,000 users. Their previous agency had built the app without any growth instrumentation: no deep links, no referral mechanics, no event tracking beyond basic app open counts. Their first UA campaign had spent £40,000 and acquired 8,000 users with a 30-day retention rate of 11%. They came to Brantum to rebuild the app and the growth strategy simultaneously.

We started with a two-week diagnostic: analysing the existing app's analytics (what little existed), mapping the user journey, identifying where users were dropping off in onboarding, and auditing the app store listing. The findings were clear: onboarding was losing 60% of users before they reached the app's core value. The referral mechanism was buried four taps deep. The app store screenshots were not communicating the value proposition. And the UA campaigns were optimising for installs rather than day-7 retention. We fixed all four.

DELIVERABLES

INDUSTRY

Project Research

The referral mechanics research was particularly valuable. Through user interviews and session recording analysis, we identified that the app's shareable output — a generated report that users sent to friends — was being used organically by 23% of existing users despite zero product encouragement. This was the referral loop waiting to be activated. We redesigned the post-generation screen to make sharing the primary CTA, added a reward mechanic for referred sign-ups, and deep-linked the shared content back into the app so referral attribution was trackable.

For the UA campaigns, we rebuilt the event tracking framework first — implementing AppsFlyer with server-side event validation and passing day-7 retention events back to Meta and Google as optimisation signals. This meant the algorithms were optimising for users who actually stayed, not just users who installed and churned. Creative was A/B tested at volume: 24 creative variants across 4 audience segments in the first four weeks.

Project Results

90 days after relaunch, the client had 50,000 active users — 6.25x the users their previous agency had acquired with the same budget. CPI was £0.32 (vs £5.00 previously). Day-7 retention was 38% (vs 11%). The referral loop was generating 28% of new sign-ups at zero marginal cost. App Store rating improved from 3.1 to 4.6 following the onboarding redesign.

The client used these metrics to secure a £2M angel round and has since expanded the UA budget to £300,000 per month while maintaining sub-£0.50 CPI. The growth infrastructure built during the Brantum engagement — the tracking framework, the referral mechanics, the creative testing process — continues to operate and compound.

Testimonials

What Our
Clients Say

Brantum is the only agency we've found that truly understands both sides. Our engineers love working with them because they speak tech. Our CMO loves them because they drive results.

Sarah K.

CTO, Series A SaaS Startup

We hired three agencies before Brantum. What took six months of back-and-forth between dev and marketing now gets done in six weeks by one team who actually communicates.

James T.

Founder, B2B Platform

Page 5 to position 1 for our core keywords in 4 months — and they shipped our entire v2 product at the same time. One team doing both is a genuine superpower.

Alex R.

CEO, FinTech Startup