Context:
Jennis is a consumer fitness app built around Jessica Ennis-Hill's training philosophy, launched June 2019.
The problem:
The brand identity was already signed off by the time UI work started, but a static identity and a working product are two different things.
The tension: does the brand actually hold up on screen, at different sizes, in different orientations, in motion, and can the product structure carry both a fitness app's functional demands and a growing content programme without either one compromising the other.
Key decisions:
Decision 1: Workout navigation and information design
What we considered: How much information to surface during a workout, next exercise, rest periods, progress, and how that needed to adapt across portrait and landscape use.
Why we chose this: Daily-use fitness apps live or die on whether the in-workout experience is clear enough to follow without breaking focus. This meant designing how users moved between exercises, how rest periods were communicated, and how the layout held up whether someone had the phone propped up landscape or in hand portrait.
What we accepted: More design complexity to handle two orientations properly, rather than designing for one and letting the other degrade.
Decision 2: A component-based editorial system, not just a marketing funnel
What we considered: Whether the marketing site should be a straightforward conversion funnel, or built to also carry a growing content programme, articles from nutritionists and physios, a magazine-style section.
Why we chose this: The brand's secondary goal, alongside sign-ups, was building a sense of community. A rigid funnel-only site would have no room for that content to grow. A component-based editorial system let the magazine section scale independently of the core funnel.
What we accepted: More upfront system design work, rather than a simpler, faster-to-build funnel page.
Solution:
Tested the brand concepts for legibility, scaling, and rendering across devices before applying colour, type, and logo to page designs. Designed the core app experience, onboarding (developed with the app dev team), workout navigation, exercise information display, rest period handling, and portrait/landscape behaviour. On the marketing site, designed a conversion-focused homepage and a component-based editorial system to support an evolving content programme.
Outcome:
The app and marketing site launched in June 2019 alongside significant press coverage (Vogue, Stylist, Sky Sports, national tabloids) driven by Jessica Ennis-Hill's profile. The content system worked as intended, with new workouts and articles added over time. Despite some technical teething problems, the app was successful and gained a devoted following.
In 2021 the product pivoted focus to cycle-mapping. The original build, from an external dev team, had significant quality issues and was eventually fully rebuilt by a different development team. The design format and structure carried over unchanged, a strong signal the underlying UI and content architecture were sound independent of who built them.
Reflection:
The original development partner should have been swapped out sooner. Communication ran through a single account manager rather than directly with developers, the dev team itself changed personnel more than once, and turnaround speed came at the cost of accuracy, it made an already tedious process inefficient. It was outside my control as a designer, but it's a clear lesson in how much a good build partner matters to how a design actually ships.
