Any comments or advice would be much appreciated. I'm usually an iOS dev so cutting my teeth on web dev again… a lot has changed in 4 years. If anyone is interested: it's hosted on heroku using flask and SQLAlchemy for the web app, Twilio for SMS and redis for queueing messages.
1) It's not their machine, or they're not signed in for automatic syncing, so getting a link on their device that takes them straight to the app store listing is easier.
2) I very rarely let a link to the app store open up iTunes on my laptop so again an SMS message is quicker to getting it on my device.
3) With the above points you could just say, "search for the app on the store", but in lots of cases (from an iOS point of view) it can be difficult to find the app.