Table 1. Technical considerations for mHealth apps.

Type of technology		Advantages	Limitations
Mobile apps, relative to older technologies such as paper and desktop computers		• Remote, synchronous and asynchronous mobile data collection • Automatically calculated variables and decision support • Decreased risk of human error • Faster interoperability with other electronic systems • Real-time monitoring and evaluation • Facilitated access to and by underserved populations • Replaces consumables such as paper and pens	• Poor performance in remote environmental conditions • Time and development for start-up • Difficulties in appropriation by end users • Stakeholders must acquire capacity or outsource app development and support • Poor compatibility with some other systems • Lack of infrastructure • Cost of technology • Risk of obsolescence
OS	Android	• Open source • Significant community support for development tools • Wide variety of prices and capabilities	• Security vulnerabilities • Lack of standardization because of multiple “flavors” of Android OS • More complex interactions and usability issues
	iOS	• Most familiar to some target users • Simple user interaction	• High device cost • Development is expensive
Development alternatives	Open-source customizable tools	• Rapidity of development • Lower learning complexity • Community support	• Lower level of customization • Greater need to train users • Database hosted on external servers
	Proprietary customizable and cross-platform development tools	• Standardized data management • More stable customizations • Attention to usability	• Development and functionality control may be limited or require significant skill to customize
	Tools developed from “scratch”	• Flexibility in design and development • Fully customizable • Highest user flexibility	• Complex development • Need for highly trained developers • Need for specialist usability designers • Significant debugging and need for updating and support
Approach	Interactive text messaging	• Lower cost of cellphone • Ease of use	Restrictions in the type of content (i.e., text or simple media only)
	Smart phone app	• Capture of more complex data, e.g., photos • Greater potential for automated decision support • GPS for localization	• Higher cost of data transmission • Complexity can affect usability

Abbreviations: app, application; GPS, global positioning system; mHealth, mobile health; OS, operating system.