Ever try to use something just a little too big for you? Shoes a half size too large, pants that require a belt, a phone with a screen a bit too wide for one-handed typing with your thumb?

If your iPhone 6S with its 4.7-inch display (or especially your iPhone 6S Plus, with its 5.5-inch display) is a little too large for comfortable one-handed typing, Microsoft might have the answer for you. The company's new iOS keyboard app, Word Flow, is nearly identical to the innovative Windows Phone keyboard. And after using it for two days with my iPhone 6S, I think it's a substantial improvement over Apple's basic keyboard. However, there are a few missing components that will prevent it from becoming my daily keyboard app, at least for now.

Word Flow has many of the features you'd expect from a keyboard app. In addition to offering word suggestions to save you typing time, and learning your most frequently used words, the app lets you swipe to spell by dragging your fingers across the required letters. Word Flow seems to predict the correct word more often than not. Swiping isn't a new idea—apps including Swype and Swiftkey already incorporate it—but it's got added power in combination with the Word Flow feature that is unique: Arc Mode. 

Arc Mode is a keyboard layout that's designed to make one-handed typing easy. It transforms your keyboard from the classic rectangular grid into an arc of keys that sits on whichever side of the screen you prefer. The rounded shape is ideal for thumb typing with one hand, and even scrolling through its spinning emoji wheel is cool, though the weird layout means a steep learning curve. In fact, you probably won't spell anything right in your first few texts, though you'll get the hang of it within a day.

I think Arc Mode beats other solutions for one-handed typing that I've seen, which typically compress the keys to one side. That strategy does make it possible to type with just one thumb, but the cramped keyboards lead to lots of misspellings.

So what's holding me back from from adopting Word Flow as my daily keyboard? First is the lack of support for time-saving iOS keyboard shortcuts. Secondly, the app lacks support for Apple's diverse emoji. Holding your finger on any of the emoji is useless, which is a huge disappointment. 

It's not perfect, but Microsoft Word Flow, created by the company's experimental projects division, is a great alternative to the standard square keyboard, and it could be the best choice out there for straphangers looking to send some texts.