On some Android keyboards (for example), the main display is a full QWERTY keyboard with numbers or symbols under the letters. You can either press directly on a letter to type it, or swipe down on the letter to type the associated number/symbol. This allows you to enter numbers/symbols much faster than if you had to switch to a separate numbers/symbols pane. Is there any third-party iOS keyboard with this functionality?
FancyKey by Pinssible Labs allows for this, and is the best replacement keyboard for iOS I've used. Setup is simple, and turning on Swype is as easy as switching to the FancyKey Keyboard, tapping the gear icon, and tapping the "Swipe input" switch on. Your keyboard with default to the custom keyboard until you change it by tapping the globe icon.
Not exactly what you are asking, but the MessagEase keyboard from Exideas allows you to type numbers by holding down the corresponding virtual key. The keyboard itself is a 3x3 swipe keyboard where each "button" naturally corresponds to a number.
The image shows me typing the number 3 by holding down my finger on the
(You can switch to an explicit number keypad by tapping the 123 symbol on the right.)
Swiping diagonally between two "keys" selects the corresponding symbol, and a tap on one of the keys selects its main symbol. This makes much better use of the limited real estate on a small mobile screen, and is much more generous with how precisely you have to position your fingers. It obviously takes a while to learn (in my case I would estimate maybe three weeks, but it was many years ago that I switched over).
It's still somewhat imprecise; I find myself producing an
e instead of a space a lot, and some swipe combinations are slightly unergonomical (left parentesis can be a drag, and I kept writing "nurber" a lot above); but I would estimate that it has reduced my keyboard swearing by 80%.
Unfortunately, the keyboard seems to crash several times per day, and the authors no longer seem to respond to support emails or their Twitter. Still, I never want to switch back to the QWERTY keyboard on my phone.