Improved help & single-letter removal protection

If you ever build software supposed to be used by other people, there are three possible outcomes:

1. You're an absolute genius and you build perfection. You're not my friend. You're not even the same species as me. I don't know what you're doing here, frankly.
2. The software is so simple and deterministic that there's no possible way it can be used in an unexpected fashion. Congratulations, you just wrote ls.
3. The first user who does anything with what you built will do something that'll make you say "oh I didn't think about that". The second will do something that actually breaks whatever you did. The third will somehow manage to make your MP3 player crash their fridge. The fourth will load their entire fridge contents as MP3. The fifth will assume your MP3 player is actually an Instagram client. Then it gets worse.

The only, and I mean this literally, the only way to deal with 3 (which is the only realistic scenario) is what the cognoscenti call "shadowing": you pick a random person off the street, place them in front of your software and make them use it (through begging, cajoling, blackmail, appeal to the better angels of their nature or what have you) and watch them while they use it. 

Shadowing is the process through which you can finally understand why your ecommerce platform has turned into a Tinder clone, or why only people in the 29-32 age bracket seem to use it. Shadowing is also the process that allowed me to realize that my (perfectly legitimate, of course) expectations about the usage of Wordrush were completely off the mark.

What happened is that, a couple days ago, a friend was over for tea and I told them I had made a small game that might be fun, and do you maybe want to have a go since it also supports Spanish? Sure, they say, so I give them my phone with the game loaded and showing the first help screen. They look at the video and start playing. 

Of course, they then proceed to complain that it's too difficult and there are no words anywhere and what to do, so I look at the screen and immediately spot a word (in Spanish. Which I don't know) and they're like "oh but you don't have to go straight?" and I'm like "erm no, that's kind of the whole point - I tried to explain that in the second help screen". To which they reply "What second help screen?" and I am enlightened.

Because, see, my developer brain assumes that most humans are developers. They might be temporarily inconvenienced developers who can barely turn on a computer, but surely they're able to notice that tiny little blue border that sort of lurks right near the edge of the screen and correctly infer that there's another help screen there? As it turns out, the answer to that is "no". They can't. Even if they could, they wouldn't, because apparently they're not really developers and even if they were they still wouldn't because their neurons and glia and whatnots are all busy thinking about literally everything else that is not my game.

Since I'm very much not an absolute genius, and I have no interest in dumbing down Wordrush (there's plenty other dumb word puzzles that are vastly smarter than Wordrush, and if you're reading this you know them all), the end result of this experience is that I decided that I needed to do something to make it a little bit more obvious that there's more stuff to read and understand about Wordrush when I'm not there to explain it to you.

Only time will tell if my ambitious plan of having people read *at least* the first two help screens worked, but I hope that those "there's more" stickers go at least some way towards that goal. If they don't, I swear I'm going to add a recording of myself patiently explaining the gameplay and force everybody to listen to it at least once. Be prepared, because the stage after that is a VIDEO of myself.

As a side note, I also added a thingamajig to prevent involuntary submission of individual letters in the Daily and Challenge modes.
It's a perfectly legitimate strategy that let me compose stupidly long words that were only missing the first of the "Next up" letters, so you can still do it (by tapping the letter a second time before it's deselected); what these changes deal with is the scenario where fat fingers inadvertently click a single letter of the word you're pointing out to, say, your spouse. 
This is recoverable in "Tap" selection mode (since you can proceed and tap on a million letters, get an error and start from scratch) but in Swipe mode you'd end up with a new letter in place of the one that was mistakenly selected, a word you can no longer complete and a spouse laughing uproariously at your lack of dexterity and general incompetence (not that it would ever happen to you, but it happened to me. Repeatedly.)

So, anyway, that's two improvements for the price of one and I figured it was worth writing this ridiculously long explanation.