On the phone app there is no tips and notes section, no hovering over a word, no hearts and no giving lingots. We're pretty much on our iwn to deduce meanings, sometimes after many mistakes. Btw, what do people use lingots for anyway, everyone seems to live them. I have about 600. What good are thet?
Although the tips cease pretty early as you advance in your tree, they help SO Much. Mistakes are inherent to the immersion process, but without any guidance it certainly would result in many mistakes. As to Lingots, many members like to buy the Streak Freeze. And then they buy another Freeze immediately after they have used the one in place. I'm pretty sure you can only buy one at a time (and you might have to do a lesson the next day before being protected by a Freeze. I have never bought one. But I have lost streaks! Another good buy is a test, although I have only taken three tests and I've been a member for 3+ years. I think it costs 25 Lingots per test. Once you start the test, you can't stop; I believe it takes 20 minutes. As you take it, it really let's you realize what you don't know very well or at all! You only receive a percentage score and you're not advised on what sentences you missed so you can't study them for another test, but I imagine it would be a different test anyway. One member suggested taking the test every two weeks.
I don't know if this is a linguistic rule, but I think in general you can expect a verb to be irregular if it is a very old/basic verb. Just like in English (compare verbs like e.g. to be => he is, to eat => I ate, to see => she saw etc.). Essen/fressen are very old/basic verbs, so there is a good chance that they are irregular. Newer/more complex verbs like e.g. surfen (to surf) or verhindern (to prevent) are more likely to be regular. There might be exceptions though as some irregular verbs were turned into regular verbs (e.g. bellen (to bark). Until the 19th century, we would have said "der Hund boll" (the dog... bork :D). Today, we say "der Hund bellte" (the dog barked)).
What about the new movie that just came out, which is I think called "The secret life of dogs?" If the dog in the story or some animated animal were telling the story, then you would need the first person conjugation.
Besides, dictionaries always show all conjugations, whether they are likely to be used or not. Same with declensions, as far as I know.