I'm thinking of getting tinder while I'm still in love with my ex.
Why are you in love with your ex?
Because he is an amazing person.
It's good to try to move on from a previous relationship, but if you aren't over your ex, that's not fair to your new potential partners. They will feel annoyed and frustrated that you are so preoccupied with your ex instead of thinking about them.
I saw the app and I'm going to use it next week.
Move on to someone else before getting with another interest. You should explore your feeling deeper and make sure that is how you really feel. Your ex isn't going to get back with you just because they see your are dating.