Call them personal assistants or just handy lifesavers—either way, their services don’t come cheap. But then again, neither does your time for that matter. Thankfully for those who can’t afford someone to book appointments or manage their topsy-turvy schedule, a number of apps promise to offer similar functionality.

Tame the clutter of your professional life. Evernote lets you take virtual memos on-demand. You can store text, photos, voice recordings (even and add location tagging) and automatically synchronize updates across your computer, smartphone, and tablet. Keyword, tag, and text searches make for easy information retrieval.

2. reQall

Helps you juggle daily to-do lists, save sudden flashes of inspiration, or remember errands to run by letting you record notes via voice, text, email or instant message. Once jotted down, you can organize action items by location, date or time, and even assign tags, categories, keywords and locations for easier cataloguing. Programmable reminders even tell you what to do right on time, or on the spot.

LinkedIn’s app transforms business cards into virtual contacts, so you can store and share them on mobile devices, and quickly pull up people’s online profiles. Shockingly, instead of high-tech scanning solutions, real humans transcribe the information, ensuring optimum accuracy for your address book.

At $20, OmniFocus is more expensive than most apps but it's worth it. This time management suite is designed to make plotting your daily agenda simpler. It's capable of organizing tasks by groups, contexts, tools, locations, and resources, and it synchronizes between multiple devices.

This popular list-making utility keeps you from forgetting tasks and outstanding action items. You can organize deliverables by priority or due date, and receive reminders via email, SMS, instant messenger, etc. Big plus: easy integration with mobile, Web, and desktop apps (Gmail, Google Calendar, Outlook, iCal, etc.) and synchronization across multiple devices.

6. Gist

Another way to organize, manage and update your ever-growing crush of contacts in a single location with minimal fuss. Capable of importing email, phone, and address data from multiple sources (inbox, social network, smartphone, etc), Gist makes keeping up with acquaintances’ constantly-shifting details painless. If that's not enough, you can also view their Facebook and Twitter feeds without exiting the app.

Goes beyond the iPhone’s basic calendar app to provide weekly overviews (day-, month-, year- and agenda-based overviews available as well) with support for extensive customization. OCD types will appreciate the loads of extra details like drag-and-drop or cut-and-paste plotting and color-coding.

A graphical organizer that lets you save notes, build to-do lists, and assign color-coded tags, fonts, icons, and backgrounds for more effective cataloguing and categorization. From travel itineraries to conference schedules, you can plot it all on a nicely-appointed calendar, and add photos, maps, sketches, and assorted images. You can also create folders and assign unique passwords for faster grouping and storage.