InstaEx is described as 'instant anonymous cryptocurrency exchange. Convert crypto to crypto or fiat to crypto instantly at best rates. Change Bitcoin, Ethereum, Litecoin, Monero and other 150+ coins' and is a cryptocurrency exchange in the bitcoin & cryptocurrency category. There are more than 25 alternatives to InstaEx, not only websites but also apps for a variety of platforms, including Android, iPhone, Mac and Windows. The best alternative is Electrum, which is both free and Open Source. Other great sites and apps similar to InstaEx are Coinbase, Bisq, Kraken and SimpleSwap.io.
InstaEx is mainly a Cryptocurrency Exchange but alternatives to it may also be Crypto Wallets. Filter by these if you want a narrower list of alternatives or looking for a specific functionality of InstaEx.
Electrum is an easy to use Bitcoin client. It protects you from losing coins in a backup mistake or computer failure, because your wallet can be recovered from a secret phrase that you can write on paper or learn by heart.