Adding supported file type in windows phone 8.1 - windows-phone-8.1

Question

I have added four file type association in my package.appmanifest file
in which .pdf is one of them. Due to this when i am clicking on any
external pdf file, My app is also coming in the list along with Adobe
reader. What could be the reason.
Following is the code of my app.manifest file
<?xml version="1.0" encoding="utf-8"?>
<Package xmlns="http://schemas.microsoft.com/appx/2010/manifest" xmlns:m2="http://schemas.microsoft.com/appx/2013/manifest" xmlns:m3="http://schemas.microsoft.com/appx/2014/manifest" xmlns:mp="http://schemas.microsoft.com/appx/2014/phone/manifest">
<Identity Name="195c0ec0-b933-4837-99c7-30250bbd0f9b" Publisher="CN=etu10" Version="1.0.0.0" />
<mp:PhoneIdentity PhoneProductId="195c0ec0-b933-4837-99c7-30250bbd0f9b" PhonePublisherId="00000000-0000-0000-0000-000000000000" />
<Properties>
<DisplayName>eBasta</DisplayName>
<PublisherDisplayName>etu10</PublisherDisplayName>
<Logo>Assets\StoreLogo.png</Logo>
</Properties>
<Prerequisites>
<OSMinVersion>6.3.1</OSMinVersion>
<OSMaxVersionTested>6.3.1</OSMaxVersionTested>
</Prerequisites>
<Resources>
<Resource Language="x-generate" />
</Resources>
<Applications>
<Application Id="App" Executable="$targetnametoken$.exe" EntryPoint="eBasta.App">
<m3:VisualElements DisplayName="eBasta" Square150x150Logo="Assets\Logo.png" Square44x44Logo="Assets\SmallLogo.png" Description="eBasta" ForegroundText="light" BackgroundColor="transparent">
<m3:DefaultTile Wide310x150Logo="Assets\WideLogo.png" Square71x71Logo="Assets\Square71x71Logo.png">
</m3:DefaultTile>
<m3:SplashScreen Image="Assets\SplashScreen.png" />
<m3:InitialRotationPreference>
<m3:Rotation Preference="portrait" />
<m3:Rotation Preference="landscape" />
<m3:Rotation Preference="landscapeFlipped" />
</m3:InitialRotationPreference>
</m3:VisualElements>
<Extensions>
<Extension Category="windows.fileTypeAssociation">
<FileTypeAssociation Name="text">
<DisplayName>text</DisplayName>
<SupportedFileTypes>
<FileType ContentType="text/xml">.xml</FileType>
<FileType ContentType="application/pdf">.pdf</FileType>
<FileType ContentType="application/zip">.zip</FileType>
<FileType ContentType="application/zip">.ebs</FileType>
</SupportedFileTypes>
</FileTypeAssociation>
</Extension>
<Extension Category="windows.fileTypeAssociation">
<FileTypeAssociation Name=".pdf">
<DisplayName>pdf</DisplayName>
<SupportedFileTypes>
<FileType ContentType="application/pdf">.pdf</FileType>
</SupportedFileTypes>
</FileTypeAssociation>
</Extension>
</Extensions>
</Application>
</Applications>
<Capabilities>
<Capability Name="internetClientServer" />
<Capability Name="removableStorage" />
<Capability Name="picturesLibrary" />
<Capability Name="musicLibrary" />
<Capability Name="enterpriseAuthentication" />
<m3:Capability Name="contacts" />
<m3:Capability Name="appointments" />
<Capability Name="sharedUserCertificates" />
<Capability Name="videosLibrary" />
<DeviceCapability Name="location" />
<DeviceCapability Name="proximity" />
<DeviceCapability Name="webcam" />
</Capabilities>
</Package>

Answer 1

Well it's normal that your app is listed there as you supported that file extension. If you expected that your app opens the file alone, that's not possible in Windows phone as defining default file opener is not supported