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Awesome! This is the exact post I am looking for and also it is a nice read. I do have another phone in spare which can be used as a cold storage and I also consider this as an alternative option in receiving crypto for smaller amounts and for daily transactions. 
However, I decided to just purchase Ledger Nano S as my main wallet in storing most of my crypto for long term hold. After that, I'll set up my current Android phone as the "watch-only wallet" and the other as "cold storage wallet". Is this is a good idea?
First, you already ordered a hardware wallet that can be used to sign your "daily transactions".
Secondly, if you want to separate your long-term hodling, you can just make a second Bitcoin account through Ledger Live or second wallet with different derivation path (to second account) via Electrum.
Lastly, that was suggested to the topic OP who's already got a spare phone and not planning to buy a hardware wallet.