I thought I could contribute a bit here.
I used Tinder pre-pandemic and got lucky with a nice relationship out of it. After break-up (during pandemic) I used it again and as many already said it turned out to be a bot filled app, it is a waste of time.
During covid times, Bumble gave me two one-night-stands and a couple of FWB situations that lasted a few months. As mentioned girls here are more internationally-minded.
I tried it again a few months ago but I was not getting anything out of it. Anyways I would say it is the best option at this moment for the average gaijin.
Other apps (pairs, omiai, coffee meets bagel) did not gave me any results.
Worth mentioning Hello Talk too, it's a defacto dating app. Used it years ago and got lucky, not sure how it is today.
IRL situation (day/bar game) I totally agree with didi521 message. It sounds simple to say and I am the most introvert person, but if you feel good with yourself and have a normal approach to a girl it might give you better results than approaching her with the annoying nampa-style (not saying Nampa doesn't work). Just try and if it doesn't work a quick 失礼しました and move on
In bar situation I think it's relatively easy to get Line if you are in certain roppongi places but from there to meeting her again it's a long way. And also it's a waste of time just going out in roppongi to get girls IMO
Also if you can speak Japanese you can try 合コン but be indirect and polite and do your move after it is finished if the feeling was good during the izakaya time.