I'm on day 41, yay! I'm struggling because, as I finish up Unit 3 which is supposed to be about clothes, there's been barely any practice for those words. In this unit I've seen some variation of "tapadh leibh, Anndra agus Iain" at least 20 times, but I've seen "geannsaidh" twice. And the second time, it was on one of the exercises where there are no hints, so I got it wrong. No learning there. What gives?
Halò! That's absolutely true. I'm also learning Gàidhlig in Duolingo and this app can't give enough language practice, unfortunately, only basic words and phrases. So I try to find other resource for learning and still practice with Duo my basic level.
From my Gaelic classroom - this is what it says for unit 3
3-1
Introduce yourself - new
3-2
PRACTICE
3-3
Ask how people are - review
3-4
Use basic phrases - review
3-5
Describe clothes - new
LESSON 1
orm, lèine, lèine-t, sgiort, bròg, seall
LESSON 2
briogais, bòtannan, còta, ort, bonaid, drathais
LESSON 3
ag iarraidh, a' ceannach, dreasa, speuclairean, geansaidh, uaireadair
LESSON 4
sinn, iad, stocainnean, fèileadh, aodach, seacaid
3-6
Introduce yourself - review
3-7
Ask how people are - review
Most of this is reviewing things introduced in previous units (I've deleted out all the words listed for these) and the only new bit are the first section called 'Introduce yourself' and 3-5 which is the clothes bits (which should be reviewed in subsequent units). So I guess the labels are right even if they only describe a small part of the unit BUT it's definitely an improvement on the original beta of this layout which was totally without any labels or indication what you might learn and to me was just depressing in seeing how far you still had to go.
It wasn't a complaint about the amount of new material in Unit, but just a comment about it 
Indeed, it's useful to familiarize yourself with the inscriptions and instructions for the lessons.
I just don't know why it depresses you how much I or someone else have to learn in subsequent lessons, because it's informative and interesting
No matter what, I'm not going to stop halfway, because I'm interested in learning Scottish Gaelic