A practical starting point for a website-based app: check the mobile experience, adapt navigation, and test the tasks customers come back for.
Suppose you run a booking service. Customers already choose a time, pay, and manage their appointments on your website. You'd like them to have an app so they can find their next booking quickly and receive a reminder.
Much of what they need already exists. A useful place to start is to see how those same tasks work on a phone.
Try a complete visit
Open your site on a phone and make a booking. Sign in, choose a time, pay, then find the confirmation. Go back and change something. Notice where you have to zoom, where a button disappears behind the keyboard, or where you lose your place.
These problems will follow the website into an app. Fixing them first improves the experience for browser visitors too.
Give navigation some attention
A website-based app displays your existing pages inside a mobile application. The website continues to handle bookings, payments, and accounts. The app can provide native navigation and push notifications around those pages.
That arrangement needs a little editing. If the app has a Bookings tab, the website's large navigation header may be redundant on that screen. An app-install banner can go too. Keep information customers still need, including support and privacy links.
Then check the transitions. Where does the back button take you after payment? Does a notification open the relevant booking? What does someone see while a page loads?
Start with a few familiar tasks
For a first version, concentrate on the things customers return to do. In this example, that might be making a booking, checking an appointment, and changing account details. Test each from beginning to end on both iOS and Android before submitting the app for review.
This is the approach we use at SiteCargo. Your website supplies the pages; we add the mobile layer around them. Changes to those web pages remain part of your normal website work. Changes to the app itself may still need a new release.
Try the result with a few regular customers. Watching someone find their next appointment will tell you more about the navigation than another round of rearranging tabs.
Try your website as an app.
Create an app draft