Crumb: From initial development stage to Top 17
applications in Health & Fitness Germany in 5 months

Brand Story

Crumb is a Hamburg-based fintech health startup mobile application based on the idea of rewarding users for health & fitness activities. The service plays a huge role in marketing for local businesses as well, since businesses are providing discounts for activities of users within the app — which builds a very healthy referral system and helps the product and local businesses to grow rapidly.


Deliver high-quality market-competitive mobile application within the tight deadline to meet investors expectations & fundraise to continue product development .


We took the product over from another developer — in fact, CTO of the product who was not too knowledgeable within the mobile development space which led to enormous timelines, bad quality of the application & wrong technology pick in the first place connected with the concept of the app

We had several initial calls and decided to rewrite the whole product from scratch using native iOS development technologies — HealthKit integration was one of the main reasons for us to make this kind of decision since the app was built using cross-platform React Native technology and provided integrations for this library through React Native were not on point — unstable, low-quality solutions. At the same time, the integration of HealthKit within the native iOS environment is very easy and straightforward.

We took the whole thing from scratch using the design provided by the client & started to iteratively work on the product. We had daily calls with updates using the Scrum process, where we discussed product functionalities and future vision for it.

Under circumstances of a tight deadline, rewriting product from scratch & fixing issues after the previous development done (we’ve also provided the backend for this new solution) we were able to fit into 2-month time frame with the launch of the application on the AppStore — in fact, TestFlight version was fully ready within 1.5 months and was already being tested for 2 weeks within the test group to get initial users’ feedback & improve the product on it.


The application got developed, tested & launched. We kicked off localization work & Android app development, improving the iOS product in parallel.

The results were terrific. Thankfully to Crumb marketing & referring strategies within the market, laser-focus target market group & thoroughly work on the users’ feedback we were able to get to Top 17th of German Health & Fitness AppStore page — the product was competing with multi-million dollar application, and MVP was built within 1.5 months with under $20k budget. Awesome users’ review is the best validation of the work done.

And there are 308 of them within this time frame!

Product Plans

We have lots of things planned for the service — both from the software & hardware points of view. New wearable devices are being manufactured right now to improve the user experience of the service and branding of the service.

We’re using COVID-19 times to polish the product, work with the test group, get more businesses on board and make sure one’s quarantine and lockdowns go done.

The service will be up & running. A major release is planned upon the end of this period & we’re expecting it to bump up after people would be allowed to get outside again.

Saad Saaed

Founder & CEO @ Crumb

“Within its first nine weeks, the app received 8,000 users and a 4.7-star rating. The platform is well-designed and hasn’t had many bugs. Interexy LLC is fast and efficient at building new features as well as taking scope changes in stride. Expertise and responsiveness are hallmarks of their work.”

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