Staying organized is pretty important. You always want to stay on task and get things done so you aren't forgetting things or wasting time doing things that you don't need to do. There are plenty of ways to create to-do lists and such, and now with the advancement of technology, we have all sorts of apps that work very well in helping you stay organized.
One of the not-so-popular apps on this list, at least for to-do lists, Google Keep. With Google Keep you can not only take notes, but also create lists of things that need to get done and help you stay on task. With Google Keep, you're able to color-code notes and lists so that you can make red for work, blue for personal, etc. Making it easier to stay on task and get organized.
Any.do To-Do List & Tasks List
Any.do is a pretty popular app for keeping up with a to-do list. Any.do has a pretty minimal design, although it's not material design. It also supports cloud sync. So you can keep up with your lists of things to do on multiple devices, seeing as they sync instantly. You can also drag and drop items so you can plan your day ahead of time.
GTasks: Todo List & Task List
GTasks is another one that is pretty popular. GTasks actually integrates with Google Tasks (which in itself is part of Google Calendar) and syncs across your devices using your Google account. GTasks is in material design, and puts your tasks front-and-center for you to get stuff done. One feature that GTasks has over the others on this list, is that tasks added within the app will appear in Google Calendar. Meaning that's one less app you need to install on your desktop.
Wunderlist: To-Do List & Tasks
Wunderlist has been around forever and is a go-to to-do list app for many people. It's available on just about every platform imaginable, even desktop. Wunderlist will sync your tasks between your smartphone, tablet and your computer, making it easier to stay on track and get stuff done. Additionally, you can attach PDF's photos and other attachments to the items on your list.
Might be a bit outdated, when it comes to the design, but Tasks still works and works well. It's pretty minimal, giving you a way to add items to your to-do list and stay on task. You are able to select multiple items at a time and have them completed. You can also have multiple lists available, as well as reordering them by dragging and dropping them.
Basically a competitor with Google Keep, Evernote allows you to take notes as well as make to-do lists. This way everything is all in one app. Evernote is great for adding tasks to your to-do list, and having separate notebooks makes things much easier to keep separate. Evernote is free, although there are paid subscription plans that do give you even more features - mostly more storage each month.
While it may not be a proper to-do list app, Microsoft OneNote does allow you to make to-do lists within the app. OneNote is also a note-taking app, as is hinted by the name. OneNote syncs with Microsoft Office 365, so you can access your notes and lists anywhere on just about any platform. Including iOS, Android, Mac OS X and Windows.
Todoist: To-Do List, Task List
Todoist is a crowd favorite. It's a free app that is very extensive. You can set up different projects. For instance you can have one for personal tasks to get done, one for work and another for a grocery list. Each task you complete gains you some Karma points. These points don't help you get anything really, but they are designed to motivate you to use Todoist more and get more stuff done in less time. Todoist is free, but there is a paid version which is $29/year.
Swipes - Plan & Achieve Tasks
Swipes here, allows you to automatically collect all of the tasks you need to get done. It also has you reorganize them so you can get everything done when it needs to be done. Keeping things nice and simple. Swipes gets its name from the gestures that are used to finish off tasks. A simple swipe to the right to complete it. You can also snooze tasks for another time of the day or even another day. Much like you can in Google's Inbox.
1-3-5 To-Do - Manage tasks
To-do lists can sometimes seem daunting. Especially if you have a lot to do. 1-3-5 To-Do aims to make that endless list of tasks a bit less daunting by giving you 1 big task, 3 medium tasks and 5 small tasks for the day. That way you don't have an endless list of tasks and still get some stuff done, before wasting the entire day away. It's quite clever, and actually works really well, in practice.
Another good app for staying organized, Centrallo allows you to make both lists and notes within the app. Making it easy to have everything in one place. You can also add photos and links into these lists and notes, which really takes advantage of the flexibility of this organizational app. Centrallo is free, but there are options to go premium and get more options. Premium starts at $4.99 per month or you can pay for a full year at $49.99.