Apart from electrum wallet,
Please provide suggestion as how to store BTC securely for long term.
Have you tried Bitcoin Core yet?
https://bitcoin.org/en/downloadThere are so many advantages to Bitcoin that almost all Bitcoin users recognise them, and I'm no exception.
You can read about Bitcoin Core for yourself here.
linkIf you want to be secure, you need to spend a little money to buy hardware wallets such as Trezor One, Trezor T, Ledger HW.1, Ledger Nano S, Ledger Blue, KeepKey.
For all types of bitcoin wallets, I recommend visiting the
Bitcoin Technical Support board.
For small transactions, I prefer Blue Wallet.
Regarding Blue Wallet, you can discuss in this thread
[Tutorial] BlueWallet - Bitcoin Wallet Discussion