Nothing reliable that I know of. To have any hope at all of being able to do that with Android you'd need a rooted device. Without root access "your" phone isn't something you can reasonably hope to secure since Google, your phone carrier, and the manufacture all have privileged access to your device while you don't. Even with a rooted device I'd only use an app that you trust. The default samsung keyboard that phone came with out of the box was downright adversarial so at least I got rid of that, but I don't think of cell phones as something I can really secure or trust in a meaningful way.