Crypto Miso is a helpful tool to see Github activity for about 100 different cryptocurrencies. You can sort by developer activity over the last 3 months, 6 months, 9 months, and 1 year.
Some of these charts will show a lot of activity as you can see the GitHub activity for both INS (Insolar) and NULS below.
This data should not be considered absolute, but should be some helpful data that might help you avoid some of the scam coins or tokens out there.
The lack of recent Github commits here makes me wonder whether these projects are still alive, or whether or not they have the funding to continue to develop a strong project.
Not all developer activity is reported to Github, so this can not be considered complete data or financial advice. This is just another crypto research tool that might be helpful now or in the future.