The main difference is that Bit-Chat is developed using BDK and primarily supports Bitcoin on-chain payments. On the other hand, Bijli is developed using LDK and offers a broader range of features, including the ability to pay Bolt11 invoices, create Bolt11 invoices, open payment channels, pay zero-sat invoices, on-chain payments as well, and more.

That's why it's a non-custodial Bitcoin and Lightning wallet ⚡