To get things done, keep it simple
I've been round and round about this. I've tried dozens upon dozens of to-do list apps and applications, including Things and Wunderlist, over the past 3-4 years. Every one of them fell short in one way or another, most often due to the way they implemented (or didn't implement) syncing. Sometimes they fell due to the weight of their own capabilities, extracting more time from the user in fidgeting and futzing with the program than in being productive with it—which is the whole objective in the first place.
After all that research, what I've decided to do, at least for now, is to use the note-taking app Notesy in conjunction with a strategy called Autofocus (Google "Mark Forster"), to be more productive. And it's working!
It cannot be overemphasized how important syncing is if you've got more than one device. As a person with multiple Macs, multiple PCs, an iPhone and an iPad, it's imperative that I be able to enter information as quickly and efficiently as possible, wherever I am and whenever I need to enter it, using the most convenient or otherwise effective device available, and then be able to both access and edit it on any of my other devices as well as the original, without delay, reliably. Most often that "most efficient data entry device" is a Mac, for the simple reason that I can type on it much faster and more accurately than with any of the others. In addition, it handles distractions and multitasking better than the other devices. So, given a choice, I will always enter information on a Mac. But that's hardly a requirement.
What Notesy does is sync any text file over Dropbox as soon as it's created or edited. That means you could enter data into your MacBook, pick up your phone, and read what you'd just written there. Or vice-versa.
Theoretically, this is also possible with any of a number of other programs (such as Evernote), but in my real-life experience things don't work nearly as well as the theory. Many times I have gotten to the place where information I had entered previously was required, only to be left frustrated with an old version of the document that refused to sync up and update. Often the problem is that the file can be edited in one direction but not the other (e.g., can be read but not edited on the phone).
All of these frustrations and roadblocks are eliminated with Notesy.
Would it be more convenient to use an app that allows for selecting items via checkboxes instead of having to key them in every time, that remembered priorities or store layouts automatically, or that allowed for custom or preassigned fields and/or tags? Sure. But the advantages those things bring pale in comparison to the essential needs: speed and reliability. And in some cases their advantages are pyrrhic, such as when using a predefined checkbox is actually more cumbersome and time-consuming than simply typing in a short word. If there's one thing I regret, it's that it took me so long to overcome the app vendor-fed fear of typing, and figure that out.
I use this app for more than just to-do lists (called by me "action lists," of which the master repository is called "action" and the distilled daily list is called "focus"). Shopping lists are probably the second biggest use I (as well as most people) have for it. Groceries, hardware, gifts, wine, you name it, I list it. And there are other things: callback lists, restaurants, prospective buyers, books to read, movies to see, emergency information, temporary check register, temporary deposit slip, medication list, places to visit...what can't be done with a text file? It's great, bordering on exhilarating, to be able to have all that with me everywhere, reliably, no matter what form I want it in. Finally!
In short, it turns out that simplicity is a definite virtue. And simplicity is what Notesy has. Not too much, and not too little.
