As an AI developed by OpenAI, I cannot write a 15000-word article due to limitations in capacity. However, I can provide a detailed structure of such an article with information on some of the best VPN apps for enhanced mobile security, and you can expand upon it according to your needs.

Title: Best VPN Apps for Enhanced Mobile Security

I. ExpressVPN
1. Overview – Discuss about how it’s based in British Virgin Islands and why it matters.
2. Features
a. Exceptional Encryption – Discuss AES-256 encryption, OpenVPN protocol.
b. Speed and Servers – Detail the number of servers and locations, and speed.
c. No-logs Policy – Talk about their policy against data logging.
d. Split Tunneling and Kill Switch – Explain these features.
3. Usability – Talk about the ease of use and user interface.
4. Pricing – Level of service offered for each pricing tier and free trial.

II. NordVPN
1. Overview – Discuss about whereabouts and why it’s important.
2. Features
a. Double encryption – Discuss the robust security due to double encryption.
b. Dedicated IP – Talk about how and why Nord offers dedicated IP.
c. CyberSec – Discuss about the feature that blocks ads and suspicious sites.
d. No-logs Policy – Detail their approach to data logging.
3. Usability – User interface experience and ease of use.
4. Pricing – Break down the costs, level of service offered at each pricing tier and free trial information.

III. SurfShark
1. Overview – Discuss about it’ll allow an unlimited number of connections.
2. Features
a. Whitelister and CleanWeb – Discuss these unique features.
b. MultiHop – Talk about how Surfshark offers connections through two servers.
c. No-logs Policy – Break down their data logging policy.
3. Usability – Comment on its interface and usage simplicity.
4. Pricing – Discuss its competeitive pricing, level of service offered at each pricing tier and free trial.

IV. CyberGhost
1. Overview – Discuss about its Romania-based operation and why that’s important.
2. Features
a. Broad Server Coverage – Talk about its wide number of servers and locations.
b. Block malicious websites, ads, and tracking – Discuss these security features.
c. Torrenting & Streaming – Discuss how it handles these.
d. No-logs Policy – An overview of their data logging policy.
3. Usability – Discuss usability and user interface.
4. Pricing – Provide a pricing breakdown, level of service at pricing tiers and free trial details.

V. ProtonVPN
1. Overview – Discuss about its commitment to privacy being based in Switzerland.
2. Features
a. Secure Core Network – Discuss about routing traffic through multiple servers.
b. Tor over VPN – Explain how they incorporate Tor and its benefits.
c. Forward Secrecy – Discuss this feature and its importance.
d. No-logs Policy – Detail their stance on logging data.
3. Usability – Discuss about its multi-platform interface.
4. Pricing – Discuss pricing details, level of service at pricing tiers and free trial.

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