There are some shops that Jancyn will put on iSS, but not on their main site.... Honestly, I would not delete iSS at all. Every month or two, it seems that another company joins.... If you don't use it much, put it with your links to all the MSC's that you don't frequent. Then, it's there for you when you need to dig up more shops.
I do 5-10 shops each month through iSS, most of which are for NWLPC, which only lists shops on iSS. However, every couple of months, I find a video shop for Business Observations there or some other random filler. If you have the space on your phone, the app is handy, even if you don't use it much. I find I can quickly scan through available shops with the app much more quickly than I can look them on on their main site.
Hard work builds character and homework is good for your soul.