IoTeX is a project meant to bridge the gap between future IOT devices. It works much the same as IOTA's proposed solution, however, they prefer to utilize side chains rather than a DAG-based tangle approach. It's arguable whether this makes them any better of a solution, and this creates a problem.
While they claim to cater to a different niche, the details behind that are still foggy, and it doesn't appear they have much to bring to the table other than a different algorithm.
IoTeX is targeting smart home applications that will allow for users to create their own subchains in order to preserve privacy. They also present autonomous cars as a use case, which would allow these vehicles to communicate with different providers privately within their own sub chains. While they present some interesting use cases, the fact is that they don't really stand out.
IOT is the newest buzz word though, and that doesn't mean they won't make any gains, however, for those looking to make an IoTeX investment, they should be careful that they don't buy into a pump, only to be sorely regretful later.
While there's only a few exchanges where you can buy IoTeX, there's at least one high volume and highly reputable option available on which to do it. Bitcoin holds the bulk of the liquidity here, but there's also some wiggle room using Ethereum and US Dollar Tether if you would prefer to use one of those assets to make your trade.
This is an Ethereum based asset known as an ERC20 token. That means that you'll need a wallet that can store these tokens in order to secure your investment. There's a ton of options available for this including several hardware wallet options like Ledger, but you could also use Meta Mask or even a multi-asset option such as Coinomi for Android and iPhone. Make sure to always back up your wallet file or seed in order to protect your investment.