Help.cant find installed app in 8.1 Lumia 520

[gr8gizmoguru]

Actually I had Hike messenger installed in my Lumia 520 but after 8.1 update, i cannot find it in my applist. Its there as when messages come I can read n reply from the app thru notifications, but if I close it, I lose it again.also I can get updates when its available in marketplace and even updated once but cannot find it anywhere. Its not showing in Storage Sense also cannot see when I connect it to Pc. What should I do?