Is it cheating if you find out your S.O. has Tinder downloaded on their phone?

So I needed to find this puzzle game my boyfriend had on his phone years ago so I went into his App Store on his phone, and the most recent searched and downloaded app was Tinder... we've been together for two years but last month I asked for just a little space, no time off but just a little space.. and he goes and tries this app?!? When I confronted him he said he "really thought I was done with him and not coming back..." wtf!! I know I didn't catch him talking with any girls but what if he is just really good at hiding it... I'm freaking the hell out...