Discovering, downloading and playing around with a fantastic app you didn't know existed can make any day brighter, particularly if it helps you do better work, faster. Here are several which should be on your radar.

Duet Display (iOS)

Created by ex-Apple engineers and ranking in the top 25 paid iPad apps in the world, Duet Display lets you use your iPad as a second display for your Mac or PC. It also enables you to use an iPad Pro and Apple Pencil as a graphics tablet. Competitors include Air Display and DisplayLink.

Cost: $9.99 at Apple's App Store

Reminder (iOS)

This iOS app was designed as a replacement for Apple's default Reminders app and features a more beautiful and functional user interface, as evidenced by the fact that the app has been downloaded several thousand times. You can use a location or one of your contacts to set up a notification when you arrive or leave there. You can also be alerted at a specific time. Other features include the ability to add notes to reminders, shake to undo last action and a dark mode. Competitors include Apple's Reminders app, as well as Google Keep, Todoist and Evernote. 

Cost: $1.99 at Apple's App Store.

Revolar (iOS and Android)

This app works with a quarter-sized device that's faster than using a smartphone to get help if you feel unsafe. With one click you can send a location snapshot and an "I'm here" message to chosen contacts. With two or three clicks contacts can be alerted with location information and custom instructions on how to provide help. Revolar recently partnered with New-York based brand, Cerimani, to create a line of personal safety jewelry. Revolar has raised over $5 million in VC funding, graduated from two Techstars programs in 12 months, and launched nationwide with Brookstone, Target, T-Mobile, Amazon and Competitors include Wearsafe and Ripple.

Cost: The Revolar device is $39.99 or $79.99 (smaller and with more features) and the Revolar Safety Jewelry Collection by Cerimani is available for presale at $99; the app is free and there is no monthly charge

No Zero Days (iOS and Android)

This app is for people who want to be better human beings. It's has a simple grid of four categories: created, helped, learned, health. Every day, when you do something which fits into a category you just tap it and the app keeps track so you can see over time which days you were doing those kinds of activities. If you press and hold a category, you can include a note about what you did for the day. Bonus features include visualizations of your activity over time, the ability to swipe to the right to view your notes and frequency by category, change your four primary categories and export or import your data. Competitors include, everydayCheck and Habitica.

Cost: $1.99 (with half of the profit donated to the American Foundation for Suicide Prevention)

SwiftKey (iOS and Android)

Every wonder what the native keyboard is thinking when it autocorrects stupidly? This smart and customizable keyboard learns your writing style over time to become more accurate. You can type by swiping instead of tapping and personalize stickers with text or use your own photos and save your favorites. Competitors include Gboard and Grammarly.

Cost: Free

Canva (iOS and Android)

This graphic design tool is a simple way to create a variety of graphics such as social media images, invitations, cards, posters, logos, flyers, presentations, blog banners, email headers, and photo collages. The app offers templates which can be personalized with your own images, text, fonts, and colors as well as a library of more than 3 million media assets, with free elements such as illustrations and fonts. Its photo editor feature lets you add filters, adjust brightness, contrast and more. You can also share your creations directly to social media, save to your device and share via email, text or WhatsApp, as well as order professional prints using Canva's print-on-demand service. The app has more than 10 million monthly active users across 190 countries. Competitors include Adobe PhotoShop, Artboard Studio, Placeit, PicMonkey and Shutterstock.

Cost: Free