I would also add: Since the big 3 (E/M, Shell and BP) went over to the Presto App, be aware that for folks like me who do shop in rural areas, the cell service can be absent or one bar of service. So, my suggestion is this - as you are approaching your shop, check your cell service. I have learned from doing several shops that they have no cell service at the site but do have enough a mile or less away from the shop. What is important is to login to the app as soon as you are close enough. and have service. It releases the shop and you can go on your merry way. Plus, when you do arrive, if you do have service, you can resubmit that you are at the site.
I have found for many of these no service sites that they (strangely) almost always ask about rewards if they are Shell shops. As you become a seasoned veteran, you realize those sites have no service and that they undoubtedly will ask for the rewards. Meaning, of course, you have to give them their rewards reward. So, just login near enough with cell service, write down the code and do the shop.
Also, because I do these rural shops without service, I cannot do them on my phone. So, I load my photos into my laptop (that I always take with me) and finish the shop at home or somewhere that I can get WiFi.
I have other suggestions but will leave that to others (unless they do not mention them).
And BTW, SA, how kind of you!